FERROMAGNETIC-RESONANCE LINEWIDTH OF FE ULTRATHIN FILMS GROWN ON A BCC CU SUBSTRATE

The ferromagnetic resonance (FMR) linewidth DELTA-H is a parameter used to characterize ultrathin film quality. The frequency-independent part, DELTA-H(0), reflects the contribution of magnetic inhomogeneities. The linear part is caused by the intrinsic Gilbert damping mechanism. Recently we have found that the lattice reconstructions of substrate templates strongly affects the FMR linewidth. bcc Fe(001) films (approximately 10 ML) were grown on unreconstructed fcc Ag(001), bcc Cu(001), and on surface reconstructed bcc Cu(001) templates. Fe layers grown on unreconstructed Cu templates exhibited an isotropic FMR linewidth. Fe layers grown on reconstructed Cu templates, on the contrary, showed an anisotropic behavior in both the zero-frequency FMR linewidth and the intrinsic damping parameter. Other magnetic parameters such as uniaxial and 4-fold anisotropies are also discussed.